Hybrid nanostructures derived from silica, or siloxanes have been the focus of intense research due to the unique possibilities to combine the properties of the organic moieties with those of the siloxane or silica matrix. (References 1-3.) Reliable synthesis of 2 to <100 nm sizes of these hybrid particles with a narrow average size distribution would provide opportunities to tailor organic moieties and polymer ligands (ranging from small molecules to functionalized molecules/dyes) in manners depending upon the applications. Difficulties in functionalization of nanoparticle surface with various types of ligands and difficulties in dispersion in specific polymer matrices are the key factors slowing down the use of ligand-functionalized nanoparticles into applications.
Recent research on organosilica hybrids, ormosils or silsesquioxanes and bridged silsesquioxanes has provided examples of tailoring various types of organic moieties onto particles for a wide variety of applications. (Refs. 1-3.) Such organosilica particles and/or bulk materials have potential applications as nano-fillers in polymer systems for use in adhesives, coatings, composites and dental fillings. (Ref. 3.) Significant advances have been made towards their use in fuel cells, optic devices, and sensors, much of which is carried out from bulk materials. (Refs. 2-4.) Recently, methods to take advantage of such hybrid nanoparticles have been much advanced by pioneering work from a few research groups. (Refs. 1d, 6, 7.) Nonetheless, it is highly desirable to tailor electronically active organic functionalities in such hybrids in terms of their potential applicability towards optoelectronic devices including photovoltaics. It would accordingly be desirable to prepare electronically active ligand-functionalized siloxane nanoparticles, such as a series of donor- and/or acceptor-functionalized siloxane and bridged-siloxane nanoparticles.